LightHeaded 

As stated in the addon description, this is accomplished using DoubleWide, another addon available here. LightHeaded without it just looks silly, hence why my screenshots are taken like that.

It's another addon. In that screenshot it's Gazmik Fizzwidget's Levelator, specifically.

Unfortunately Armory does some really nasty thing with the quest log and until they stop doing that there isn't all that much I can do =(.

Unfortunately, this addon will need to alter its behavior. Updating the quest log this frequently is completely wasteful and unnecessary and obviously causes issues.

Yes, and none of this requires repeatedly scanning the quest log, considering absolutely nothing changes without an event firing. You can either believe me or not, I'm not going to continue trying to convince you.

Whether or not Lightheaded should be doing something different, or Quest Helper should be doing something different I can't tell right now as I didn't dive into the code. I would think though, the light headed being a mod that only runs when the quest log is open, vs a mod that is running all the time ... that light headed should change.

This just doesn't make sense to me. LightHeaded needs some way to know that you've selected a new quest. The _ONLY_ reliable way to do this is via the SelectQuestLogEntry() function. I'm not particularly sure why you're fighting me on this, but QuestHelper calls SelectQuestLogEntry in an OnUpdate function, which is causing the issue. There is absolutely and 0 way for me to "fix" this problem, whether you like that or not.

I have already disabled lightheaded cause Quest helper is what I consider an essential mod for question ... and lightheaded functionality I can get from alt-tabbing. I would like to not have to alt tab ... but based upon that comment, that is my only choice.

Or you could do what I said, and talk to the author of QuestHelper to get the issue resolved. The quest log scanning that is being done is absolutely unnecessary and there is no way to work around it.

I responded answering your question, and you came back and told me that I was wrong, basically. Forgive me for not taking that very well.

Second, it's not my place to tell others how to code or how to fix it. If it's a simple fix, you as a developer can talk to them.

I barely don't have time to develop my own addons, or do my own work, let along contact other authors to explain why what they are doing is causing issues with my addons. Feel free to have the author get in contact with me and I'll speak with him.. but I can't do all of the running here.

Lastely, this is not a pissing match to see how's code is right or wrong. If YOUR code needs everyone else to be "pristine" for it to function correctly, then yours will only be used in "pristine" environments. When I write objects for production software, I don't assume anything and write stuff knowing other developers objects will most likely function in the worst possible scenario where my objects are concerned. Take that any way you want ... I am done here. Maybe there is nothing you can do on your end, and I don't desire to learn yet another programming language. Personally, for this user, I will use the mod that is the most valuable to me ... this mod is off the list ... sorry.

Wow, this is about the rudest thing I've ever read. Why would you think you can just waltz in here and continue to tell me that I'm wrong when you obviously haven't even spent 15 seconds looking into the code to see what is wrong. You will find that I am one of the most accommodating authors out there always willing to work hard to make things work well for my users. Since you REFUSE to figure out how things work and regardless continue to tell me that I'm not only wrong, but somehow doing you a disservice let me explain exactly what is happening here and WHY this doesn't work.

The Quest API returns data about the quests in your quest log but requires the quest to be "selected" in order to return something like the description or rewards. Every X seconds, QuestHelper scans through the quest log and selects each quest in order to obtain information about it. When it is done, it sets the quest log selection back to the original selection.

The only reasonable way for LightHeaded to detect the quest selection changing is by hooking the SelectQuestLogEntry() function, which is the one I'm discussing above.

The _problem_ is, QuestHelper doesn't need to do this. The information it needs to get can be gotten from the API without needing to scan through each of the quest log entries, in particular through watching events.

I'm not really sure what the problem is here, and why you're being so combative, but I'm doing everything I can to try to help here.

Sorry if that's not good enough for you.

That would be an addon calling LightHeaded, but not being updated to work with the new 2.4 API. Do you have another quest addon that might not be updated yet?